Weight



(No Model.) O. S. WHEELWRIGHT.

DIGESTER OB. CONVERTER, &c.

Patented Mar. 9, 1886.

' Witnesses:

UNITED STATES PATENT CFFICE.

CHARLES S. WHEELWRIGHT, OF PROVIDENCE, RHODE ISLAND.

DIGESTER OR CONVERTER, 800.

SPECIFICATION forming part of Letters Patent No. 337,720, dated March 9, 1886.

Application filed July 13, 1885.

To all whom, it may concern:

Be it known that I, CHARLES S.WHEEL- WRIGHT, of Providence, in the State of Rhode Island, have invented a new and useful Improvement in Digesters or Converters Used in Producing Chemical or Mechanical Results under Pressure or Otherwise, of which the following is a specification.

I make the outer shell of the digester by bolting together sections of cast-iron, each section, except the two forming the ends, being in the form of a band flanged at both edges and slightly curved inward between the flanges, and thus the inside of each section is convex and the outside concave. The bolts pass through bolt-holes in the flanges. Similar conical ends provided with flanges complete the shell. 1 line the digester with sheets of lead, one for each section and end, securing them in place by clamping each two adjoining edges in the seam between the two sections of the shell.

One object of the invention is the economy had from using cast metal instead of wrought metal for the shell. Sufficient strength is given to each section by casting it in the concavo-convex form above mentioned, the swell being inward to resist a greater pressure from within than from without.

Another object of the invention is the maintaining a perfect fit of the lining to the interior of the shell of the digester, as hereinafter set forth.

In the drawings, Figure 1 is an elevation of a digester constructed according to this invention. Fig. 2 is a partial section at a joint or seam enlarged.

A A A A are the flanged castings from which the main body or cylinder of the digester is made. B B are the end pieces, and C C are caps. The flanges are marked a and the bolts b. The lead sheets are marked L, and a strainer is marked S.

Pipes communicating with the digester are marked 1? p,- but it is unnecessary to explain their several uses.

I insert a ring packing in the several seams Serial No. 17].,567. (No model.)

inside of the bolts; but the particular form of packing used is not of my invention. It is shown clearly in section at Fig. 2, the part marked 12 being of lead, and the fillings (marked 1" r) being of rubber.

The extreme ends of the convex portions of the castings are arcs of true circles of small diameter, the intermediate portions being in a curve of large diameter. This curved form of the interior of each section insures an accurate fitting of the lead sheets in the first instance.

The thickness of the castings will depend upon the pressure under which they are designed to be used. For ordinary usein the manufacture of wood pulp, for examplethey may be made of iron about two inches thick. When made of compound metal, they may be of less thickness than when made of iron. Each section being of a given measurement between two seams and of a given weight of metal, its strength is increased by the concavoconvex form given to the casting. Thelining may be a quarter of an inch thick, or evenlcss. For some uses a lining may not be required, or at least no lining will be required further than the scale formed on the inside of each section in casting.

I claim- 1. A digester in sections of cast metal bolted together, the said sections swelling inward in concavo-convex curves at right angles to the seams between them, and having outwardlyproj ect-in g flanges, by which they are bolted together, substantially as described.

2. A digester having its outer shell in sections bolted together and provided with a lining, also in section, the inner faces of the said shell-section being in convex curves at right angles to the seams between them, and the lining being clamped at said seams, substantially as described.

CHAS. S. WHEELWRIGHT.

Witnesses:

EDWARD TRIPP, GEORGE B. PHILLIPS. 

